Hi Pauline,
Well I'm glad to see another VJ member here who has decided to go back to the UK! James and I will be going for my settlement visa in early June.
As for the consulate, it's easy to find. It's 845 Third Ave b/t 51st and 52nd. As for landmarks, it's near the UN and just a few blocks northeast of Grand Central. Third Ave goes in the uptown direction. 51st goes west, 52nd goes east. I don't drive, so I don't know about coming in from outside the city, but I hope this helps a bit.
Good luck on moving back. I'm so excited!
Alexis